I think if you are interested in Critical Care then you should go for it. I was a new grad in the PICU and although I felt overwhelmed at times, I learned really good assessment skills, I learned to pick up on the small details that can make a difference. I learned a tone of other skills such as wound care, trach care, foley insertion, lab results ( your patients will have daily even hourly labs), medication calculations, lots of medication administration. Most of the time your patient is intubated, so learning all about respiratory management, Blood gasses. Since most of your patients are intubated you will learn how to communicate with family members. You will do A LOT of teaching, especially regarding medications, plans of care, importance of changes in the plan of care.
I really wanted the ICU, so although it was hard, I had a good orientation program, had tons of reading, and still did reading after orientation. It is fast paced becuase your patient is really that sick, you have to understand why your patient needs all of that equipment to keep them alive, how does it keep them alive, and how their diagnosis relates to all of it.
You will have to put in your effort to learn, and not just ask your preceptor all the time for questions, you should look up first and then ask questions based on what you have learned.